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Cardinal表征门控振荡器

2023-08-30 14:49:57 

Cardinal Components IncCharacterizing Gated Oscillators

Measuring Stability And Envelope Shape In Gated Oscillators

Gated or keyed oscillators are turned on and off rapidly. This type of operation often causes frequency changes or “chirps”. Characterizing the keying characteristics and frequency stability of gated oscillators is an easy job for LeCroy oscilloscopes with the jitter and timing analysis package.

Figure 1 shows a typical measurement on a 315 MHz keyless entry system transmitter. This type of device uses a keyed continuous wave (cw) transmitter to send digital information to the receiver located in a vehicle. Data is encoded by controlling the width of the burst.

Of interest to the designer is the shape of the gated burst envelope and the frequency variation as the oscillator is keyed. The shape of the envelope affects the spurious content of the signal. Likewise, frequency or phase modulation of the carrier caused by the gating the oscillator affects signal purity. Either of these effects can result in out of band signal components and a potential for failure to meet emissions certification requirements.

In figure 1 the leading edge of the transmitted waveform is captured in channel 2 shown as the top trace. Trace A contains the extrema math function called roof, which extracts the peak values of each cycle of the transmitted signal. This trace is used to evaluate the risetime of the burst. The risetime parameter appears on the first line of the parameter readout located directly below the displayed traces.

Trace B, third from the top, contains the JitterTrack function of frequency and shows the variation in frequency as a function of time. Note that the frequency converges to the nominal 315 MHz in about 250 ns. The bottom trace contains the JitterTrack of cycle to cycle period variation. Both of these functions allow the user to specify the amplitude threshold and hysteresis level. This allows the user to start the measurement only after the signal has achieved a reasonable level. The threshold level appears as a dotted horizontal line of the source waveform(CH2). Note that the JitterTrack function do not start until the threshold level is achieved. This avoids errors caused by reading noise at the beginning of the waveform.

Cardinal表征门控振荡器


Cardinal表征门控振荡器测量门控振荡器的稳定性和包络形状

门控或键控振荡器快速打开和关闭。 这种类型的操作通常导致频率变化或 “唧唧喳喳”。对于带有抖动和定时分析包的勒克罗伊示波器来说,表征门控石英贴片晶振的键控特性和频率稳定性是一项简单的工作。

图1显示了一个典型的在315MHz上测量,无钥匙进入系统发射机。这种设备使用键控连续波发送数字信号的发射器给接收者的信息位于车辆中。数据是通过控制爆发的宽度。
设计者感兴趣的是门控脉冲的形状包络和频率石英晶体振荡器的变化键控。的形状包络影响杂散信号的内容。同样的, 频率或相位调制造成的承运人的门控振荡器会影响信号纯度。这些中的任何一个 影响可能导致带外信号分量和未能满足的可能性 排放认证要求。

Cardinal表征门控振荡器

在图1中,前缘传输的波形是 在通道2中捕获,显示为顶部轨迹。跟踪A包含 极值数学函数 称为roof,它提取每个周期的峰值传输信号。这个痕迹是 用于评估的上升时间爆裂。上升时间参数出现在第一个 参数读数的行 位于正下方 显示的痕迹。

迹线B,从上面数第三个, 包含抖动轨迹 频率和的函数 显示了中的变化 频率是时间的函数。 请注意频率 收敛到标称值315 大约250纳秒。这底部轨迹包含 周期到周期的抖动跟踪 周期变化。这两个功能允许用户 指定振幅阈值 和滞后水平。石英晶振这允许用户启动 测量仅在 信号已经达到合理水平。阈值水平 显示为水平虚线 来源行 波形(CH2)。请注意 抖动跟踪功能不启动 直到阈值水平被 已实现。这避免了错误 由读取噪音引起 波形的开始。


小体积晶振 厂家 型号 Description 参数 频率稳定度
CSM1Z-A5B2C3-40-14.31818D18 Cardinal晶振 CSM1 CRYSTAL 14.31818MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C5-60-24.0D18 Cardinal晶振 CSM1 CRYSTAL 24.0000MHZ 18PF SMD ±50ppm
CX5Z-A5B2C5-70-7.37280D18 Cardinal晶振 CX5 CRYSTAL 7.3728MHZ 18PF SMD ±50ppm
CX532Z-A2B3C5-70-12.288D18 Cardinal晶振 CX532 CRYSTAL 12.2880MHZ 18PF SMD ±30ppm
CSM1Z-A2B2C3-40-30.0D18 Cardinal晶振 CSM1 CRYSTAL 30.0000MHZ 18PF SMD ±50ppm
CSM4Z-A2B3C3-40-12.0D18 Cardinal晶振 CSM4 CRYSTAL 12.0000MHZ 18PF SMD ±30ppm
CSM4Z-A2B3C3-40-25.0D18-F Cardinal晶振 CSM4 CRYSTAL 25.0000MHZ 18PF SMD ±30ppm
CX532Z-A2B3C5-70-16.0D18 Cardinal晶振 CX532 CRYSTAL 16.0000MHZ 18PF SMD ±30ppm
CX5Z-ARB2C5-70-7.3728D18 Cardinal晶振 CX5 CRYSTAL 7.3728MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-50-22.1184D18 Cardinal晶振 CSM1 CRYSTAL 22.1184MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-100-5.0D18 Cardinal晶振 CSM1 CRYSTAL 5.0000MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C5-40-14.7456D18 Cardinal晶振 CSM1 CRYSTAL 14.7456MHZ 18PF SMD ±50ppm
CX325Z-A5B2C5-50-20.0D18 Cardinal晶振 CX325 CRYSTAL 20.0000MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C3-40-25.0D18-F Cardinal晶振 CSM1 CRYSTAL 25.0000MHZ 18PF SMD ±50ppm
CX635A-A5B2C3-40-18.432D13 Cardinal晶振 CX635A CRYSTAL 18.4320MHZ 13PF SMD ±50ppm
CSM4Z-A2B3C3-40-10.0D18 Cardinal晶振 CSM4 CRYSTAL 10.0000MHZ 18PF SMD ±30ppm
CSM1Z-A0B2C3-50-16.0D18 Cardinal晶振 CSM1 CRYSTAL 16.0000MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C5-50-20.0D18 卡迪纳尔晶振 CSM1 CRYSTAL 20.0000MHZ 18PF SMD ±50ppm
CSM4Z-A2B3C3-40-20.0D18 Cardinal晶振 CSM4 CRYSTAL 20.0000MHZ 18PF SMD ±30ppm
CSM4Z-A2B3C3-60-6.0D18 Cardinal晶振 CSM4 CRYSTAL 6.0000MHZ 18PF SMD ±30ppm
CSM4Z-A2B3C3-60-8.0D18 Cardinal晶振 CSM4 CRYSTAL 8.0000MHZ 18PF SMD ±30ppm
CSM1Z-A1B2C3-90-8.0D18 Cardinal晶振 CSM1 CRYSTAL 8.0000MHZ 18PF SMD ±50ppm
CX532Z-A2B3C5-70-12.0D18 Cardinal晶振 CX532 CRYSTAL 12.0000MHZ 18PF SMD ±30ppm
CSM1Z-A5B2C5-40-11.0592D18 Cardinal晶振 CSM1 CRYSTAL 11.0592MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-50-15.360D18 Cardinal晶振 CSM1 CRYSTAL 15.3600MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-50-19.6608D18 Cardinal晶振 CSM1 CRYSTAL 19.6608MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C3-40-14.7456D20 Cardinal晶振 CSM1 CRYSTAL 14.7456MHZ 20PF SMD ±50ppm
CSM1Z-A0B2C3-80-13.5D18 Cardinal晶振 CSM1 CRYSTAL 13.5000MHZ 18PF SMD ±50ppm
CSM4Z-A2B3C3-40-29.49152D18-F Cardinal晶振 CSM4 CRYSTAL 29.49152MHZ 18PF SMD ±30ppm
CSM1Z-A0B2C3-50-16.257D18 Cardinal晶振 CSM1 CRYSTAL 16.2570MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C3-40-24.576D18 Cardinal晶振 CSM1 CRYSTAL 24.5760MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-50-16.000312D18 Cardinal晶振 CSM1 CRYSTAL 16.000312MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-50-18.0D18 Cardinal晶振 CSM1 CRYSTAL 18.0000MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-200-3.6864D18 Cardinal晶振 CSM1 CRYSTAL 3.6864MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C3-200-3.6864D18 Cardinal晶振 CSM1 CRYSTAL 3.6864MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-150-4.9152D18 Cardinal晶振 CSM1 CRYSTAL 4.9150MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-40-25.0D18 Cardinal晶振 CSM1 CRYSTAL 25.0000MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C5-70-10.0D18 Cardinal晶振 CSM1 CRYSTAL 10.0000MHZ 18PF SMD ±50ppm
CSM1Z-A0B2C3-50-25.175D18 Cardinal晶振 CSM1 CRYSTAL 25.1750MHZ 18PF SMD ±50ppm
CSM1Z-A5B2C3-120-6.144D18 Cardinal晶振 CSM1 CRYSTAL 6.1440MHZ 18PF SMD ±50ppm
CSM1-A1B2C3-50-20.0D16 Cardinal晶振 CSM1 CRYSTAL 20.0000MHZ 16PF SMD ±50ppm



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